test windows build with ninja

.github/workflows/packaging_wheels.yml

@@ -30,14 +30,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python: [ cp39, cp310, cp311, cp312, cp313, cp314, cp314t ]
+        python: [ cp313 ]
         platform:
           - { os: windows-2025,     arch: amd64,      cibw_system: win }
-          - { os: ubuntu-24.04,     arch: x86_64,     cibw_system: manylinux }
-          - { os: ubuntu-24.04-arm, arch: aarch64,    cibw_system: manylinux }
-          - { os: macos-15,         arch: arm64,      cibw_system: macosx }
-          - { os: macos-15,         arch: universal2, cibw_system: macosx }
-          - { os: macos-13,         arch: x86_64,     cibw_system: macosx }
+
         minimal:
           - ${{ inputs.minimal }}
         exclude:
@@ -89,14 +85,25 @@ jobs:
           cache-suffix: -${{ matrix.python }}-${{ matrix.platform.cibw_system }}_${{ matrix.platform.arch }}
           python-version: ${{ matrix.python }}
 
+      # Load MSVC environment, needed for Windows - ninja builds
+      # Without this, the linking step will fail.
+      # Note: CIBW uses the host environment for windows, rather than an isolated container
+      - uses: ilammy/msvc-dev-cmd@v1
+        if: ${{ matrix.platform.cibw_system == 'win' }}
+        with:
+          arch: ${{ matrix.platform.arch }}
+
       - name: Build${{ inputs.testsuite != 'none' && ' and test ' || ' ' }}wheels
         uses: pypa/[email protected]
         env:
           CIBW_ARCHS: ${{ matrix.platform.arch == 'amd64' && 'AMD64' || matrix.platform.arch }}
           CIBW_BUILD: ${{ matrix.python }}-${{ matrix.platform.cibw_system }}_${{ matrix.platform.arch }}
-          # PYTHON_GIL=1: Suppresses the RuntimeWarning that the GIL is enabled on free-threaded builds. 
-          # TODO: Remove PYTHON_GIL=1 when free-threaded is supported. 
+          # PYTHON_GIL=1: Suppresses the RuntimeWarning that the GIL is enabled on free-threaded builds.
+          # TODO: Remove PYTHON_GIL=1 when free-threaded is supported.
+          # CMAKE_BUILD_TYPE=Release: Override Debug default when MSVC dev environment is loaded
           CIBW_ENVIRONMENT: PYTHON_GIL=1
+          # For Windows, msvc-dev-cmd sets build to Debug. So, override it back to Release. 
+          CIBW_ENVIRONMENT_WINDOWS: PYTHON_GIL=1 CMAKE_BUILD_TYPE=Release
       - name: Upload wheel
         uses: actions/upload-artifact@v4
         with:

pyproject.toml

@@ -389,3 +389,10 @@ before-build = ["brew install ccache"]
 
 [tool.cibuildwheel.windows]
 before-build = ["choco install ccache"]
+
+[[tool.scikit-build.overrides]]
+if.platform-system = "^win32"
+cmake.args = [
+   "-G", "Ninja",
+   "--log-level=DEBUG",
+]